Rear Axle Nut Torque

[LeRox]

Im looking for the torque spec for the rear axle nuts (34mm nuts) for an 02' Z. I have seen numbers from 118 ft-lbs (suggested normal torque) to 140 ft-lbs (suggested slight overtorque) here on the forum.

Anyone know what it should be....

[dwjZ06]

Originally Posted by LeRox

Im looking for the torque spec for the rear axle nuts (34mm nuts) for an 02' Z. I have seen numbers from 118 ft-lbs (suggested normal torque) to 140 ft-lbs (suggested slight overtorque) here on the forum.

Anyone know what it should be....

118 Exactly! This is from C4C5 Specialist. I had the clicking issue. He says do not over tighten period. Check them every now and then. Don

[LeRox]

Awesome. Any recommendations for an axle grease to use on the splines after flushing out the rust (or should I not be applying grease)??? I have a white lithium grease at home that I would think would work ok.....????

I have also heard that you should use removable lock-tite on the nuts when re-installing.....???

[No Doubt]

118 Exactly! This is from C4C5 Specialist.

Not any longer. It's now 160 ft-lbs with Locktite, per the following GM service bulletin...

Subject: Tapping or Scraping Noise From Rear Wheel Area (Replace Wheel Drive Shaft Nut) #07-04-95-001 - (09/26/2007)

Models: 2005-2008 Cadillac XLR
2005-2008 Chevrolet Corvette

Condition

Some customers may comment on a tapping or a scraping noise coming from the rear wheel area.

Cause

This condition may be due to the torque on the wheel drive shaft nut relaxing over time.

Correction

Replace the left and the right wheel drive shaft nut following the procedure below.
Remove the center cap from the rim.
Remove and discard the wheel drive shaft nut.
Apply LOCTITE™ 272, or equivalent, to the threads of the axle shaft.
Install the nut and tighten to the new specification.
Tighten
Tighten the nut to 215 N·m (160 lb ft).
Install the center cap to the rim.
Important: The vehicle should not be driven for 24 hours following the repair in order to allow the thread lock to cure.
Part Number
Description
Qty

10257766
Nut
2 (one per side)


Warranty Information
For vehicles repaired under warranty, use:

Labor Operation
Description
Labor Time

F9712*
Wheel Drive Shaft Nut - Replace
0.3 hr

*This is a unique labor operation for bulletin use only. It will not be published in the Labor Time Guide.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION


© Copyright General Motors Corporation. All Rights Reserved.

[LeRox]

Uh, the bulletin you posted says its for 2005-2008 Vette's/Caddy's.....Does the 160 ft-lbs apply to C5 Z06's too???

Thanks

[No Doubt]

Although the service bulletin is for '05-'08 cars, the reason for its issuance has been the number of those cars that have had axle nuts loosen.

If your '02 has a loose axle nut there is no reason you can't torque it to the new spec, in addition to using Loctite, because the nut is the same size. And again, per the bulletin, I would replace the nut as well. Reason being: the threads may be slightly galled and the nut itself could be mishapen just enough to cause it to loosen again.

[dwjZ06]

Originally Posted by LeRox

Uh, the bulletin you posted says its for 2005-2008 Vette's/Caddy's.....Does the 160 ft-lbs apply to C5 Z06's too???

Thanks

Does not apply to 01-04 Z06. Take C4C5's advice. He does this for a living and sees them everyday! The specs above have been used for the C6Z06's You can use PB Blaster or even WD40 to clean them up. You may have to do this every few years. I did not use loctite, but have checked them a few times. They were not loose. It was just a rust issue. Take care, Don

This just back from Paul(C4C5) TSB 07.04.95.001 is for 2005-2008 Corvette.
There is NO bulletin torque specification change for c5, which all are 118 ft lbs, per SI document 975298.

[No Doubt]

As was pointed out, the bulletin I posted is for '05-'08 cars. I was well aware of that when I posted it, as well as being aware the car in question is an '02.

One need ask why it came loose in the first place and secondly, how to prevent it from loosening again. Although the bulletin was written for '05-'08 cars the same applies to an '02 with a loose axle nut. The nut is the same size and uses the same threads. Thus, from an engineering perspective there is no reason the same torque can't be used and for the same reason it is on the later cars.

Furthermore, the service bulletin was issued as the cars referenced are frequently experiencing this issue. Had earlier year cars experienced with the same frequency then a bulletin would have been issued for them as well. They didn't, and hence no bulletin. But once again, the same fix can be used should the need arise as in this case.

[LeRox]

I should note that my axle nuts were not loose and as far as I know never have backed themselves off, Im going to be doing the rust flush this weekend and wanted to know what I should re-torque the nuts to when Im finished.

[No Doubt]

In that case 118 lb-ft would be appropriate. However, once loosened these nuts can work loose easier from then on. Thus I suggest using new nuts and Lockite. Even the 160 lb-ft of torque wouldn't hurt.

The axle nuts on my '02 C5Z came loose several times after they had been removed ONE time. Take a guess as to how I fixed the issue...

BTW, the axle nuts on my '07 C6Z have never been removed and have not loosened....yet.

[dwjZ06]

Originally Posted by LeRox

I should note that my axle nuts were not loose and as far as I know never have backed themselves off, Im going to be doing the rust flush this weekend and wanted to know what I should re-torque the nuts to when Im finished.

Loctite not needed. 118 Ft Lbs. If you over tighten the result could be hub damage and some bearing issues. The clicking should go away after you get the splines clean. Don

[DJWorm]

My recommendation is a stepped process for ALL C5, C5 Z06, C6 , & C6 Z06.

A. IF either the original axle nut(s) comes loose or is rusted:

1. Remove and discard original axle nuts (both L & R per axle)
2. Clean all surfaces
3. Replace with NEW axle nuts
4. Apply Loctite 272 (Red/Orange)
5. Torque to 118 -124 FT# *
6. Let Loctite cure overnite. (24Hr @72 degrees, 48 Hr @ 40 degrees)

B. IF nut only becomes corroded again over time, only repeat above process 1-6

C. IF the nut backs off again:

1. Repeat above steps 1-4
2. Retorque to 160 FT.#
3. Let Loctite cure overnite.

* NOTES:
- Nuts & threads should be dry and uncoated (except for Loctite). After cleaning it is acceptable to use an H2O dispersant such as WD40, but the surfaces should be wiped afterwards. Using a heat gun or blow dryer is preferred rather than WD40.

-DO NOT use oil, antisieze or Loctite with antisieze.

- Loctite alone is only a very mild Lubricant. Torque values are generally NOT increased from DRY values when using Loctite. However it is acceptable to increase Torque vales by 5% when using Loctite 242, if you so desire. In this case, 118 FT# + 5% = 124 FT.#

- Apply Loctite to the first 3 stud thread rows.

- Loctite 272 can be removed with Loctite Solvent.

[No Doubt]

Loctite not needed. 118 Ft Lbs. If you over tighten the result could be hub damage and some bearing issues.

I know what you mean and you are correct as far as over torquing a bearing nut. However, there is no difference between a C5 and a C6 in this case as all components involved are the same, in fact virtually identical. Again, the reason they issued the bulletin for '05-'08 cars was the frequency of the axle nuts loosening.

If you remove the nut on a C5Z in order to clean the rust, as I did, there is a chance it may not remain tight if using 118 lb-ft. Mine didn't. Hence, I retorqued it to 150 lb-ft as I recall in addition to using Loctite 272. This was before the bulletin and in fact before the C6Z was even released. It remained tight thereafter and made no clicking noises.

Therefore, the process DJ outlined is reasonable and I would suggest following it should a torque of 118 lb-ft result in the nut loosening.

[JasonI]

I also marked mine with a paint pen so I could quickly see if it has moved. Same thing with bearing hub bolts.

[LeRox]

Well I flushed the hell out of the splines this weekend with Kroil (rust penetrant) and WD-40. Dried the threads and everything off with shop towels and then used locktite on the back 3 or 4 threads and torqued to 120 ft-lbs. Hopefully all is well now. Didnt notice any clicking on my way to the car wash that afternoon.....